The adaptable amphibious wheel-legged robot

2018 ◽  
Vol 42 (3) ◽  
pp. 323-339
Author(s):  
Jicheng Liu ◽  
Jinshuai Yang ◽  
Binglu Yan ◽  
Zheng Liu
Keyword(s):  
Large Diameter ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Legged Robot ◽  
Loop Control ◽  
Walking Gait ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Amphibious Robot ◽  
Foot Trajectory

A new category of large-diameter adaptable amphibious wheel-legged robot is proposed in this paper. The proposed mechanism can climb obstacles better than existing designs. The Denavit–Hartenberg (D–H) coordinate system is used for kinematic analysis, and the constructed kinematic model is used to solve for these joint variables for a redundant robot. The control strategy is to plan both the foot trajectory of the amphibious robot, to optimize the operational performance in special environments, as well as the walking gait. Then the closed-loop control system is used. A simulation is used to verify the usefulness of the planned foot trajectory and walking gait for an entire running cycle, and a circuit is designed to solve a communication problem between the Arduino and the AX-12 servo. Finally, the foot trajectory of a single robot leg is captured by a three-dimensional motion-capture system to verify the rationality of the foot trajectory and walking gait.

Coupled Simulation Study on the Working Device of the Excavator Based on VL Motion

2012 ◽  
Vol 229-231 ◽  
pp. 1679-1683
Author(s):  
Shao Xun Jin ◽  
Hui Peng Chen ◽  
Guo Jin Chen
Keyword(s):  
Hydraulic System ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Coupled Simulation ◽  
Device Structure ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Multi Body ◽  
Working Device

On the foundation of analyzing the excavator’s working device structure, this paper built its three-dimensional model in Catia embedded in the VL Motion, created the bodies, defined the joints and corresponding drive interface to produce the multi-body dynamic model. According to the analysis on the hydraulic system of the working device, it built the electro-hydraulic system with the interface of Motion in AMEsim and then performed the coupled simulation between the Motion and AMEsim. Aiming at the working device’s performance defects, such as the worse displacement tracking, the slow respond, it designed the PID closed loop control system to improve the system’s performance. The simulation results show that the working device’s combination performance has been improved greatly, respond speed becomes fast and the ability of displacement tracking is better.

Design and Improvement on a Stress Loading Device for Ligament Tissue Engineering

2013 ◽  
Vol 325-326 ◽  
pp. 267-270
Author(s):  
Xiu De Wu ◽  
Xiong Wang
Keyword(s):  
Tissue Engineering ◽  
Control System ◽  
Position Control ◽  
Three Dimensional ◽  
Loop Control ◽  
Ac Servo ◽  
Closed Loop Control System ◽  
Loading Device ◽  
Loop Control System ◽  
Ligament Tissue Engineering

Strain loading control is important for addressing the complex requirements of tissue engineering in bioreactor. The stress variation laws of the engineering tissue during growth were analyzed, and the strain loading rules were determined. A new mechanical stress loading device was developed, which was able to apply complex concurrent mechanical strains to three-dimensional scaffolds independently housed in reactor chambers. The AC servo control system was used to carry out tensional and rotational displacements. Well controlled mechanical stimulations could be applied to the developing ligament tissue, through the closed-loop control system for stresses, allowed different mechanical loading patterns on the scaffolds. We analyzed the strains of scaffolds fixed in circular and planar modes. The strain, motion, and position control methods were designed. This device is suitable for the bioreactor used in ligament tissue engineering.

The Development of a Three Dimensional Displacement Platform

2011 ◽  
Vol 339 ◽  
pp. 195-199
Author(s):  
Xin Li ◽  
Shen Huai Wang
Keyword(s):  
Three Dimensional ◽  
Relative Displacement ◽  
Displacement Sensor ◽  
Work Piece ◽  
Two Dimensional ◽  
Loop Control ◽  
Dimensional Precision ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Metrology System

This paper presents a novel precision three-dimensional platform based on vertical scanning that has practical application in surface topography measurement. The three-dimensional precision platform is composed of a two-dimensional platform with metrology system and a vertical scanning platform. When the work piece is measured, the closed loop control system controls the two-dimensional platform. Meanwhile, the Z direction servo motor and the piezoelectric actuator drive the vertical scanning platform to move vertically to realize the fine displacement. The diffraction grating displacement sensor detects the vertical relative displacement of the vertical scanning platform.

An Expert Controller Based on Transient Response Patterns

2011 ◽  
Vol 219-220 ◽  
pp. 3-7
Author(s):  
Ning Zhang ◽  
Rong Hua Liu
Keyword(s):  
Control System ◽  
Transient Response ◽  
Closed Loop ◽  
Performance Criterion ◽  
Response Patterns ◽  
Loop Control ◽  
Expert Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Control Decision

An expert control system based on transient response patterns and expert system techniques is proposed in this paper. Depending on the features of the closed-loop control system determines the control decision and adjusts the parameters of the controller. The proposed method requires minimal proper information about the controlled plant and, with the linear re-excitation learning method, the system is kept satisfying the performance criterion.

scholarly journals Closed-loop control system for well-defined oxygen supply in micro-physiological systems

2017 ◽  
Vol 3 (2) ◽  
pp. 363-366
Author(s):  
Tobias Steege ◽  
Mathias Busek ◽  
Stefan Grünzner ◽  
Andrés Fabían Lasagni ◽  
Frank Sonntag
Keyword(s):  
Control System ◽  
Oxygen Supply ◽  
Closed Loop ◽  
Microfluidic System ◽  
Closed Loop Control ◽  
Loop Control ◽  
Cell Vitality ◽  
Closed Loop Control System ◽  
Loop Control System

AbstractTo improve cell vitality, sufficient oxygen supply is an important factor. A deficiency in oxygen is called Hypoxia and can influence for example tumor growth or inflammatory processes. Hypoxia assays are usually performed with the help of animal or static human cell culture models. The main disadvantage of these methods is that the results are hardly transferable to the human physiology. Microfluidic 3D cell cultivation systems for perfused hypoxia assays may overcome this issue since they can mimic the in-vivo situation in the human body much better. Such a Hypoxia-on-a-Chip system was recently developed. The chip system consists of several individually laser-structured layers which are bonded using a hot press or chemical treatment. Oxygen sensing spots are integrated into the system which can be monitored continuously with an optical sensor by means of fluorescence lifetime detection.Hereby presented is the developed hard- and software requiered to control the oxygen content within this microfluidic system. This system forms a closed-loop control system which is parameterized and evaluated.

The Design and Simulation of Three-Phase PWM Converter

2013 ◽  
Vol 321-324 ◽  
pp. 917-920
Author(s):  
Guang Ya Liu ◽  
Xiao Song Li
Keyword(s):  
High Frequency ◽  
Closed Loop ◽  
Voltage Source ◽  
Pwm Rectifier ◽  
Phase Voltage ◽  
Pwm Converter ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Three Phase ◽  
Loop Control System

Three-phase voltage source PWM rectifier generally adopts double closed loop control system. According to the high frequency characteristic of three-phase voltage source PWM rectifier, this paper put forward the setting method of current inner ring regulator and voltage outer ring regulator PI parameter. Finally, it is verified by simulation.

Closed Loop Identification by Optimization Method

2015 ◽  
Vol 1084 ◽  
pp. 636-641
Author(s):  
Valeriy F. Dyadik ◽  
Nikolay S. Krinitsyn ◽  
Vyacheslav A. Rudnev
Keyword(s):  
Closed Loop ◽  
Uranium Hexafluoride ◽  
Optimization Method ◽  
Model Parameters ◽  
Control Loop ◽  
Loop Control ◽  
Identification Method ◽  
Closed Loop Control System ◽  
Closed Loop Identification ◽  
Loop Control System

The article is devoted to the adaptation of the controller parameters during its operation as a part of a control loop. The possibility to identify the parameters of the controlled plant model in the closed control loop has been proved by a computer simulation. The described active identification method is based on the response processing of the closed loop control system to standard actions. The developed algorithm has been applied to determine the model parameters of the flaming fluorination reactor used for the production of uranium hexafluoride. Designed identification method improves the quality of the product and the efficiency of the entire production.

Adaptive synchronization of uncertain fractional-order chaotic systems using sliding mode control techniques

2019 ◽  
Vol 234 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Bahram Yaghooti ◽  
Ali Siahi Shadbad ◽  
Kaveh Safavi ◽  
Hassan Salarieh
Keyword(s):  
Control System ◽  
Sliding Mode Control ◽  
Fractional Order ◽  
Chaotic Systems ◽  
Closed Loop ◽  
Sliding Mode ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System

In this article, an adaptive nonlinear controller is designed to synchronize two uncertain fractional-order chaotic systems using fractional-order sliding mode control. The controller structure and adaptation laws are chosen such that asymptotic stability of the closed-loop control system is guaranteed. The adaptation laws are being calculated from a proper sliding surface using the Lyapunov stability theory. This method guarantees the closed-loop control system robustness against the system uncertainties and external disturbances. Eventually, the presented method is used to synchronize two fractional-order gyro and Duffing systems, and the numerical simulation results demonstrate the effectiveness of this method.

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